Draft-preventing device.



W. F. CALDWELL.

DRAFT PREVENTING DEVICE.

APPLICATION FILED SEPT. 30. 1914..

1,173,555. Patented Feb. 29,1916.

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ave/141L0 0 WWW Fig/mm mzf W. F. CALDWELL.

DRAFT PREVENTING DEVICE. APPLICATION FILED SEPT. 30. I914.

Patented Feb. 29, 1916.

lm/Mam WILFBED F. CALDWELL, 013 DETROIT, MICHIGAN.

DRAFT-PREVENTING DEVICE.

Specification of Letters Patent.

Patented Feb. 2a, 1916.

Application filed September 80, 1914. Serial No. 864,219.

To all whom it may concern Be it known that I, Wmrnnn F. CALD- WELL, acitizen of the United States, and a resident of Detroit, in the countyof Wayne and State of Michigan, have invented a new and ImprovedDraft-Preventing Device, of which the following is a specification.

This invention relates to a draft-preventing device; and some of itsobjects are to prevent currents of air from enter ng or leaving abuilding through an open passageway, whereby dust may be excluded andthe temperature of the interior may be maintained substantiallyconstant; to provide means to receive the current of cold air that tendsto pass into the building along the floor and discharge 1t exterlor tothe building; to provide means for automatically causing the operatlonof the current-controlling devices when the door 1s opened; and toprovide means whereby a disinfecting medium may be applled to persons orobjects entering or leaving the building.

The invention is particularly applicable to stores, warehouses, officebuildings and hospitals, but is obviously not hmited to such structures.

The invention consists in the details of construction shown, describedand particularly pointed out in the claims.

In the drawings, which are diagrammatic I in nature, Figure 1 is afragmentary vertical longitudinal section of a bullding or passagewayequipped with one embodiment of my invention. Fig. 2 is a section on theline 22 of Fig. 1, the door being closed. Fig. 3 is a section on theline 33 of Fig. 1, showing the door and the circuits for controlling theoperation-of the motor. Fig. 4 is a section on the line 44 of Fig. 1.Fig. 5 is a fragmentary section on the line 55 of Fig. 3. Fig. 6 is alongitudinal section showing another embodiment of my invention.

Similar reference characters refer to like parts throughout the severalviews.

In the embodiment shown in Figs. 1 to 5, inclusive, 1 indicates an outerwall, 2, the ceiling, 3, a side wall or partition, and 4, the floor ofbuilding that may be of any desired construction, access to which is.had through an opening that may be closed by a door 5. As shown, thisdoor is slidable laterally upon a track 6 and, when open, is received ina niche in the wall in a well known manner, but it is to be understoodthat other types of doors may be used. The opening in the wall may beapproached over a sidewalk 8. The floor is cut away, preferably at apoint just inside of the doorway, to receive a grating 11 of anypreferred form, through the outer portion of which air may be drawn intothe flaring mouthpiece 12 that merges into the pipe 13 which leads tothe suction fan 14, preferably located in the basement of the building.The fan may be driven from the motor 15 by the belt 16 and dischargesthrough the pipe 17, the end of which is located at any desired point 18exterior to the building. In this manner, the current of cold air thattends to enter the building along the floor, as indicated by the arrows19, is sucked downwardly and discharged outside of the building withoutaffecting the temperature of the interior. Air from points above theinner portion of the grating is drawn downwardly into the mouth-piece 21which leads, through the pipe 22, to the suction fan 23 that may bedriven from the motor 15 by means of the belt 24 and discharges throughthe pipe 25. The latter leads to and extends across the upper edge ofthe doorway, where it-is perforated upon its inner lower side, asindicated at 26, to provide passages from which a blast of air isdirected downwardly and inwardly toward the inner portion of the gratingin substantially the manner shown bythe arrows 27. The heated current ofair that tends to leave the building through the upper part of thedoorway is struck by the downwardly andinwardly directed current fromthe perforations 26 and deflected in the manner indicated by the arrows28. It will thus be ,seen that a substantial barrier is interposedbetween the air in the building and the air outside, which neverthelessallows free entrance and does not tend to blow off the hatsor disarrangethe clothing of persons entering.

In some installations I provide an air filter or dust separator 29 inthe pipe 22, by means of which dust may be removed from the air blast.

Current for the motor may be received from the wires 31 through the mainswitch 32 in either of two ways: It may pass through the connecting wire.33 and manuwhich is thrown into operative position by being struck by aprojection 36 upon the door as the latter approaches its fully openposition. As shown, the switch 35 1s pivoted to the wall at 37 and isnormally held out of engagement with the contact 38 bymeans of acompression spring 39, the efi'ect of which is overcome by contact ofthe projection 36 on the door' with an arm of the switch. It is obvious,however, that other types of switches may be used.

The embodiment of my invention shown in Fig. 6 differs from thatheretofore described in the following respect :The air from the fan 23.is carried by a pipe 44, preferably through the filter or dust separator45 and temperature-changing device 46 to a point considerably within thebuilding, where it may be discharged through the register 47. As shown,the temperaturechanging ,device comprises a casing, through which theair from the pipe 44 passes, and pipes 48 whereby either steam or acooling medium may besupplied. The embodiment shown in Flg. 6 alsodiiiers from that previously described in that air for the blast isobtained from a compressor 50 that may be driven from the motor 15 bymeans of the belt 51. This arrangement allows the use of a pipe 52 ofmuch smaller diameter than the pipe 25. The compressor may'also obtainits air from the basement which, particularly in ofiice and storebuildings, is ordinarily over heated; allarge proportion of this air islater sucked through the fan 23 and discharged through the register 47,whereby economy in the heating of the building is secured. In hospitalsand other buildings in which it is desirable to fumigate persons orobjects entering or leaving, the blast pipe may be provided with adevice 53 whereby predetermined amounts of a liquid or other fumigantmay be discharged into the current of air. While this feature is shownonly in Fig. 6, it is clear that a similar device may be used in theembodiment first described.

Many changes maybe made in the details of construction without departingfrom the spirit of my invention. For example, the opening across which.the current of air is directed may be that between two adjacent roomsof the same building instead of in the exterior wall as shown; and theterm wall in the claims is used to designate either an external wall ora partition between adjacent rooms. In certain instances, also, one orboth of the suction means may be omitted, in which case the inwardlyinclined blast serves to prevent the current of air from leaving thebuilding through the upper portion of the opening in a much moreeflicient manner than would an outthe intercepted air wardl inclined orvertical blast. I do not, therefhre, wish to be limited otherwise thanas indicated by the subjoined claims.

I claim 1. In combination, a building having an opening in one of itswalls, means ,for directing a current of air downwardly across theopening, suction means comprising an intake located near the lower sideof the opening for receiving said current of air, and a second suctionmeans also comprising an intake located near the lower side of theopening for intercepting the current of air that tends to pass into thebuilding through the lower portion of the opening, said last mentionedsuction means being arranged to discharge the intercepted air exteriorto the building.

2. In combination, a building having an opening in one of its walls,means for directing a current of air downwardly across the opening,suction means comprisin an intake located near the lower side of theopening for receiving said current of air, said suction means beingarranged to discharge the air within the building, and suction meansalso comprising an intake located near the. lower side of the openingfor intercepting the current of air that tends to pass into the buildingthrough the lower portion of the opening, said last mentioned suctionmeans being arranged to discharge exterior to the building.-

3. In combination, a building having an opening in one of its walls,means for directing a current of air from above downwardly across theopening, and suction means comprising an intake located near the lowerside of the opening for receiving the current of air, said suction meansbeing arranged to discharge the air in the interior of the building.

4. In combination, a building having an opening in one of its walls, adoor normally closing said opening, means for directing a current of airdownwardly across the opening, means for supplying air under pressure tothe directing means, and means controlled by the door as it approachesthe limit of its movement toward open position for throwing the airsupplying means into operation.

5. In combination, a building having an opening in one of its walls,closing said opening, means for directing a current of air downwardlyacross the opening, 'motor-operated means for supplying air underpressure to the directing means, and electric circuits, controlled bythe door as it approaches the limit of its movement toward openposition, for conducting cur-' rent to the motor of the motor-operatedair supplying means.

6. In combination, a building having an opening in one of its walls,means for dia door normally recting a blast of air from above down- Intestimony whereof I sign this'specifiwardly and inwardly across saidopening, cation in the presence of two subscribing 10 the axis of salidglasit being arralged in a witnesses. genera y me ine irection, ansuction 5 means comprising an intake located in- WILFRED CALDWELL wardlyof the opening to receive the blast Witnesses:

' as it approaches the lower level of the L. M. SPENCER,

opening. HUGO W. KREINBRING.

